Pipe joint for water heaters



Jan. 9, 1951 v KOETTING 2,537,678

PIPE JOINT FOR WATER HEATERS Filed Jan. 24, 1948 2 Sheets-Sheet l INVENTOR.

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Jan. 9, 1951 Filed Jan. 24, 1948 F. KOETTING 2,537,678

PIPE JOINT FOR WATER HEATERS 2 Sheets-Sheet 2 IN VEN TOR.

' fie/22 KQFZTZ VG BY E Z Z ATTORNEY Patented Jan. 9, 1951 UNITED STATESPATENT OFFICE PIPE JOINT FOR WATER HEATERS Fritz Koetting, Brooklyn, N.Y.- Application January 24, 1948, Serial No. 4,099"

6 Claims. (01. 2s5 s)- This invention relates to new and usefulimprovements in heat exchangers such as a water heater for use with asuitable source of live steam.

More specifically, the present invention proposes the construction ofsuch a water heater or heat exchanger including a shell having aplurality of longitudinal tubes, and bends interconnecting the tubes,the bends and tubes being connected so that any tube may be convenientlyremoved from the shell for cleaning and repair.

Another object is to provide a boiler as aforesaid which can be readilyadapted for either parallel or series flow through the steam tubes, andwhich may employ one or more steam inlets and one or more steam outlets.The invention contemplates the provision of fittings used ininterconnecting the tubes and the bends which are constructed andlocated for convenience in removing any tube from the boiler shell.

Accordingly, another object of the invention is to provide a boiler asaforesaid equipped with improved fittings for connecting the tubes tothe shell.

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings, and to the appended claims in which thevarious novel features of the invention are more particularly set forth.

In the accompanying drawing forming a mau terial part of thisdisclosure:

Fig. 1 is a side view of a water heater constructed in accordance withthis invention.

Fig. 2 is a view of the left end of the boiler. Fig. Sis a section onthe line 3-3' of Fig. 1. Fig. 4 is a view'simil-ar to Fig. 2 showing thetubes connected in series.

Fig. 5 is a sectional view showing the connections between tubes, shelland bends.

Figs. 6, 7 and 8 are views similar to Fig. 5 showing other embodimentsof the invention.

The water heater, according to the form of the present invention shownin Figs. 1-5, includes; a shell I0, for containing water to be heated,and having end walls and I2. The shell has a water inlet l3 and a wateroutlet I4. Each end wall is provided with a plurality of threadedorifices l5, see Fig. 5. There is a bank of straight tubes 16 in theshell.

Referring to Fig. 2, it will be seen that, as one exemplification of thepresent invention, the tubes II; are arranged to two sets on oppositesides of a longitudinal center plane of theshell, the shell beingcircular in cross section. The two uppermost tubes are horizontallaligned and hav no U-bends, being open for connection with the" steamexhaust. They form the outlet 34 for the bank of tubes. These twooutlets 34 a be connected by a forked pipe if desired so that they willboth exhaust into a single pipe.

In a similar manner the bottom two pipes form the steam inlets 35.These'inlets may be sup plied from any suitable source of live steam.The inlets are shown at one end of the shell and the outlets at theother, but they may be at the same end if desired. Adjacent tubes arethen con- 7 nected in series by'U-bends 30. Thus the two sets of tubesof thebank are in parallel and'the tubes of each set are'in series. Thetubes are so spaced that they may be connected by similarbends 30. Alsothe inlets and outlets are-similarly spaced so that they may beconnectedby bands if desired. For example, the outlets 34might be connected by abend 30. Then the ends 34 of the top tubes would serve one as an inletand the other as an outlet and all the tubes of the shell would be inseries, eliminating any parallel flow.

The tubes may also 'be arranged so that their ,centers are disposed atthe apices of a pattern of equal equilateral triangles or equal squaresfor example, so that-each tube will be equidistant from at least twoother; Such an arrangement will permit the bends3ll to be-readilychanged to interconnect the tube in a new flow arrangement withoutchanging the span of any bend. One or more tubes may thus be cut out ofservice, and by suitably plugging the openings in the end walls fromwhich any such tube is removed, the boiler or heat exchanger may berestored to service while the old tube is being repaired or areplacement tube procured. More tubes than those shown may be employedif desired.

The series arrangement described may also be obtained as shown in Fig.4. A lesser number of by means of the usual tap'eredpipe threads. TubeI6 is similarly threaded into flange 53* and fits freelyin'fitting 5i.Bend 30 is also similarly threaded into flange 54. Gasket 55 areinserted 3 between adjacent flanges as indicated. Bolts 56 pass throughclearance holes in flanges 53 and 54 and gaskets 55 to engage threadstapped in flange 5|.

In assembling a tube IS in the boiler, flanged fittings 5| are firstinserted in both end plate I and I2 and are tightened in the usualmanner. A tube I6 is then slid through flanges at opposite ends of theboiler and a gasket 55 is placed over each projecting end. A flangemember 53 is then screwed over the threaded portion of each end, andtightened. The length of the tube It and the cutting of the end threadsthereon is such that thi tightening may be accomplished withoutinterference from the gasket 55 and so that the bolt holes may bebrought into alignment. Flange 54 which is threadedly Secured to bend 35is then 7 placed in position with an additional gasket 55.

Bolts 55 are then threaded into tapped holes in fitting 5|. As bolts 55are tightened, flanges 53 and54 and gaskets 55 are compressedagainst theface of fitting 5|, providing a joint which is tight against both steamand water.

The tightening of bolts 56 also compresses tube it so that it will bowslightly in the middle, and will thus be able to adjust itself todimensional changes which accompany hon-uniform.

temperature changes in the boiler or heat exchanger. v

If the bowing of tube It is not desired, a modified form of theinvention, as shown in Fig. 6, may be used. In this form, a gland orstufiing box (ii is threaded into end wall |2 of boiler l0. Any desiredform of gland or stufiing box may be used and it has been shown ascomprising an outer portion 62 shaped to receive packing 63 which iscompressed by nut 54 against the exterior surface of tube it to form awater tight joint through which tube |5 may slide. This slidingconnection permits the dimensional changes above described to occurwithout bendmg of the tube l5.

Bend 30 is secured to the end of tube i5 by the usual union 5| which isshown as comprisingtwo flanged members 65 and 66 which are held togetherby an internally threaded annular clamping member El, leakage beinprevented by gaskets 68 and 69. The ends of tube l6 and bend 30 arethreaded into the union in the usual manner.

Referring to the construction shown in Fig. 'I, a plate or disc i? issecured to the outer face ofeach end wall II and i2 and this disc I! hasa threaded orifice It in line with the orifice l5. An externallythreaded fitting I9 is screwed into the aligned orifices l5 and slightlyinto the interior of the shell l0. fitting [9 has a circular flangesuperposed on the disc with packing therebetween.

The fitting I9 is provided with internally threaded recesses 22, and afitting 23 having a flange 24 similar to the fiange 25 is connectedthereto; flange 25 being superposed on the fiange 20 with the packing 25therebetween and flange 24 having orifices in line With the recesses 22.

Bolts'21 are passed through the orifices 26 and into the recesses 22 forconnecting the two flanges together.

A pipe 28 is Welded to the flange 2:: and forms another part of thefitting and extends outwardly therefrom and is externally threaded andconnected to one leg 29 of a U-bend 30 by a union 3|, the connectionbeing sealed by a packing 32.

The fitting I9 is internally threaded at 33, at"

I8 and extends The ' 4 its ends opening into the shell. The tube I6 isexternally threaded at each of its ends and screwed into the alignedthreads 33 of two opposed fittings |9 disposed in the opposite walls IIand I2.

In assembling the tubes in the shell so that they may be removed forcleaning, inspection or repair, a fitting I9 is first secured to one endof each tube and a fitting I9 is screwed into the orifices l5 of onewall only. That is, fittings I9 may be screwed into the holes of theWall II but not into wall 12. The tubes are then slid through theorifices l5 of the wall |2 until their fittings |9 reach the orificesl5, whereupon their fittings I9 are screwed into the orifices l5 of walll2 and at the same time the other ends of the tubes are screwed into thethreads 33 of the other fittings- H5 in the wall ll.

After the tubes are in place and the flanges 2!) turned tightly againstthe packing 2|, the fittings 23 can be attached first and then the bends35 can also-be attached. The tubes may be removed by a reversal of thisprocedure.

In the embodiment of the invention shown in Fig. 8, the same advantagesare present as in the embodiments of Figs. 5, 6 and 7, but are attainedby a somewhat different construction.

Instead of the fittings l9, straight externally threaded pipes l9 arescrewed into the orifices l5 and I8 and extend beyond both ends thereof.

against the disc l1 and packing 25' against the pipe i9. Each fittingalso has a pipe portion 28' connected to a U-bend 30' by a union 3|.

From the foregoing, it will be seen thatan assembly has been providedpermittingthe ready removal of tubes for repair or cleaning', fan'd afully steam tight packed joint has been provided nevertheless. r

If the bowing of tubes is is desired, then the arrangements of Figs. 5,'7 and B'may be used.

be used.

While I have illustrated and described the preferred embodiments of myinvention, it 15 to be understood that I do not'limit myself to theprecise constructions herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention as:defined in the appended claims.

Having thus described my invention, what I by United claim as new, anddesire to secure States Letters Patent is:

l. A heat exchanger of the class described comprising a shell having endwalls, aligned threaded orifices in said end walls, fittings screwed insaid orifices and having internal threads, tubes in said shell screwedinto said internal threads of aligned fittings'so that they can beremoved from said shell by unscrewing the fitting at one end thereoffrom said end wall adjacent thereto, all of said tubes being evenlyspaced from adjacent tubes, and necting adjacent tubes.

2. A heat exchanger of the class U-bends con =4 M threads, tubes in saidshell screwed into said internal threads of aligned fittings so thatthey can be removed from said shell by unscrewing the fitting at one endthereof from said end wall adjacent thereto, all of said tubes beingevenly spaced from adjacent tubes, and U-bends connecting adjacent tubesfor forming of said tubes "and end wall orifices and a flange superposedon said disc, said flange having internally threaded recesses and saidneck having internal threads, tubes screwed into opposed neck'threads, afitting having a flange superposed on said first mentioned flange, boltssecuring said flanges together and screwed into said recesses, and a U-bend leg connected to each of said last mentioned fittings.

4. A connection for securing a tube in a shell end wall for permittingremoval of said tube from said shell, said shell end wall having athreaded orifice comprising a flanged pip-e adapted to be screwed intosaid end wall orifice and having internal threads adapted to receive athreaded end of said tube, the outer face of said flange having threadedrecesses, a flanged fitting superposed on said flange and securedthereto by bolts screwed into said recesses, said fitting having anexternally threaded neck, and a U-bend leg secured to said neck threadsby a threaded union.

5. A heat exchanger of the class described 6 comprising a shell havingopposed end walls provided with aligned threaded orifices, flanged pipesscrewed into said orifices with their flanges engaging the outer facesof said end walls, said flanged pipes having internal threads,externally threaded tubes screwed into aligned pipes whereby when afitting is unscrewed from its end wall orifice it will carry its tubewith it and un screw its said tube from the opposed fitting for removalof the tube fromthe shell.

6. A heat exchanger of the class described comprising a shell havingopposed end walls provided with aligned threaded orifices, flanged vpipes screwed into said orifices with their flanges engaging the outerfaces of said end walls, said flanged pipes having internal threads,externally threaded tubes screwed into aligned pipes whereby when afitting is unscrewed from its end wall orifice it will carry its tubewith it and unscrew its said tube from the opposed fitting for removalof the tube from the shell, a U-bend, and means for connecting saidU-bend to said flanged pipe.

' FRITZ KOETTING.

REFERENCES CITED The following references are of record in the fileofthis patent:

UNITED STATES PATENTS Number Name Date 646,050 Hirt Mar. 27, 1900661,506 Fisher Nov. 13, 1900 1,559,998 Shipley Nov. 3, 1925 1,688,921Dows Oct. 23, 1928 1,703,241 Kendall Feb. 26, 1929 1,710,530 Bell Apr.23, 1929 1,920,598 Schirmer Aug. 1, 1933 2,463,405 McMaster Mar. 1, 1949

